Re: vss2cvs migration of shared files

[Laine Stump]

Manik Bafna <address@hidden> writes:

> There are files in VSS shared across projects and
> shared between directories in the same project.
> We are migrating from VSS to CVS.
> What is the right strategy for migration of shared files.
> 
> 1. Break the link and maintain as two separate files

This is easiest in the short term, but a very bad idea in the long
term, since it requires developers to maintain two copies of the same
file.

> 2. Break the link and keep only one copy.
> This will require change in build scripts and source code.

This has the problem that you note, but seems to be the best approach
for long term sanity (when combined with option (3) for entire
directories that are shared).


> 3. Is there a way where I have only one copy
> of the file in the CVS repository and when I
> checkout I get multiple copies of the same file
>  (I'm not sure whether it is possible using modules).
> Are there any implications using this method.

You can share entire directories with entries in the modules file, but
that won't work for individual files. In VSS it is possible to share a
single file between two directories in the repository. There is no
equivalent functionality in CVS. Some people emulate it by symlinking
the ,v file in the repository into multiple directories, but doing so
is begging for trouble, since CVS sets mutex locks on a per-directory
basis to prevent multiple processes simultaneously writing to the same
,v file during commits and tags. Having a ,v file existent in two
directories breaks the data model that is assumed for proper operation
of these locks, and will eventually lead to a corrupted file.

> I'm using Laine Stump's scripts for migration.

You flatter me. I only put them on a web site and hack them now and
then ;-) The scripts were originally written by Jerry Nairn.